Google Nexus is a line of consumer electronic devices that run the Android operating system. Google manages the design, development, marketing, and support of these devices, but some development and all manufacturing are carried out by partnering original equipment manufacturers. The product family consists mostly of mobile devices—six smartphones and four tablet computers have been released to date. As of October 2014, the devices currently available in the line are the Nexus 5 smartphone, Nexus 6 smartphone, Nexus 9 tablet, and Nexus Player set-top box. Devices in the Nexus line are considered Google's flagship Android products. They contain little to no manufacturer or wireless carrier modifications to Android, although devices sold through carriers are sometimes SIM locked and may bear some extra branding. Nexus 6 devices sold through AT&T, for example, are SIM locked and feature a custom boot splash screen and a logo on the back of the device, despite having otherwise identical hardware to the unlocked variant.